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Glossary of Terms

R.F. Heat Sealing Glossary:

A     B     C     D     E     F     G     H     I     J     K     L     M     N     O     P     Q     R     S     T     U     V     W     X     Y     Z


A

alternating current - or AC
Flow of electricity which reaches maximum in one direction, decreases to zero, then reverses itself and reaches maximum in the opposite direction. This cycle is repeated continuously. The number of such cycles per second is the frequency.

amperes
Electrical current or rate of flow of electrons. The higher the amount of amps, the more power is consumed.

ampere meter
An electrical meter which measures the amount of current.

anode
See Plate

appliqué
A decorating technique used on vinyl where one piece of vinyl is applied to the surface of another through the heat-sealing process. This often is done with special custom dies so as to produce a dimensional effect.

arc
This occurs during a sealing operation, the buffer is usually damaged, either by deposits of carbon, or holes through the material. If the damage is not too extensive, the burned area may be cleaned with solvent to remove the carbon deposits, and/or lightly sanded. The reason for getting rid of the carbon is that r.f. is attracted to it and will keep on reacting to it if you don't get rid of it. The damaged area may then be patched with a single layer of mylar tape approximately .001" thick. Clean the die up also. If the damage is more severe, replace the entire buffer. Make sure the Arc Suppressor sensitivity is set to the most sensitive setting. Make sure this is working before continuing. See Surface flash

arc suppressor - also known as Arc Guard, Arquench, Arc Eliminator, Arc Anticipator.
A device that detects a voltage drop between the upper and lower plates, and instantaneously shuts off the r.f. power preventing damaged to dies. Generally the higher the dial setting, the more sensitive it is.

artwork (binders)
This is type, line art, drawings, etc., mounted on a board or produced on a diskette, giving color requirements, size, and all necessary specific directions. Photographs should be provided separately, but indicated in exact size on the art board or a "dummy" mock-up.

B

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back-bone (binders)
This is the spine of a binder or the supporting part at the back to which the front and back covers are attached. It's the part you can see when you place a binder on the shelf.

back-set (binders)
the dimension from the edge of the page to the center of a hole that has to be drilled.

bakelite (buffer) - or Phenolic
A synthetic resin and plastic made from formaldehyde and phenol. It's an insulator and used as buffer material. Paper base grades XX, XXP, XXX and XXXP in thicknesses ranging from .015" to .020" thick.

balanced material
Material coated or laminated equally on both sides.

bar
Used on bar sealer. This is used instead of a die. It can be straight or curved. Surface area is calculated by measuring length by width.

bar sealer
Machine with a flat bar instead of a die, usually not heated, with a deep throat press for sealing long seams.

bead seal
The perimeter of a heat seal where you see a "bead" finish around the edge.

binders board
This is fibre board used in the construction of case-bound construction.

boosters (binders)
These are the triggers or levers found on the ends of a metal ring which are used to open and/or close the rings.

booster cylinders
Cylinders added to the sides of existing cylinders for more pressure, used when surface area is larger and/or materials are thicker and need more compression for r.f. heat sealing to perform properly.

buffer
Insulating material used as an electrical barrier. Separates the dies and decreases arcing of r.f. . Phenolic, fish paper, glassine, teflon, glass, mylar, silicone fiberglass, etc.

C

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capacitor
Device used for storing an electrical charge. Consisting of two or more conducting plates separated from one another by an insulating material, air, or a vacuum.

cathode
See Filament

chipboard (binders)
Craft paper that has been glued together to form a firm board used to give binders their hard cover.

choke
wire coil that allows D.C. electrical flow but blocks r.f. .

clipboard
Any product using a clip to hold loose sheets.

concealed rivets (binders)
a process where the rivets holding the metal to the binder are concealed inside the cover material. This form is often used to provide a clear, unobstructed spine on which rivets will not interfere with graphics.

cold crack
Vinyl will crack under certain conditions and at specified temperatures. You have to be certain that the vinyl used in your product is properly rated so that it will not experience cracking, especially if it has to be shipped to cold climate.

conductor
Any material that allows the flow of electricity. Copper, brass, aluminum etc.. R.F. travels on the surfaces of the connections, so make sure that your power strap and grounding straps are making good surface contact with each other. Never use steel hardware inside or near the oscillator circuit.

control voltage
The voltage powering the control circuit(s).

contact
Part of a switch or relay that makes the connection and separation to open and close a circuit.

D

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D-ring (binders)
A metal ring that looks like a "D". There also are "O" rings.

dies
Rule set on a plate to seal, cut, shape, punch holes into plastic material. Usually made of brass or steel. Brass lasts longer but costs more. Surface area is calculated by measuring (width x length) of rule.

dielectric
A material , such as rubber, glass, etc., or a medium, such as a vacuum, gas, etc., that can sustain an electric field: dielectrics are used in capacitors, between adjacent wires in a cable, etc.

dielectric sealing - or r.f. sealing, r.f. welding
The process of fusing two or more pieces of PVC, compounds of : polyurethane, polyester, nylon, , polyolefine, coated fabrics etc. together with a single weld. It is accomplished through molecular friction at the frequency of usually 27,000,000 times per second (27 MHz). This friction melts the material and two pieces become one. This type of seal is far stronger than a thermal seal.

debossing
The process of using heat and pressure to smooth out an area on your material. This can be used for a stamping or additional graphics, attachment.

diode
A solid state rectifier

E

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elasticity
The quality or condition of being elastic. The springiness, flexibility, resilience of material.

emboss
This decorating technique uses top and bottom dies to create a raised dimensional effect to the graphics.

F

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fabric weight
Ounces per yard. Term used in synthetics and fabrics.

feather seal
This is a dielectric sealing method which uses a die that forces the traditional bead inside of the sealed edges.

filament/cathode
The electrode on an oscillator tube, which is the primary source of an electron stream, typically constructed of carburized thoriated tungsten wire which is directly heated by application of filament voltage.

fish paper (buffer)
Buffer, blueish grey paper material used for less critical applications. It is available in thicknesses from .005" to .020" thick.

flush-cut (binders)
It is any material that is cut exactly to size and utilizes a single piece of material to form the entire binder. This can be leather, hardboard, polyethylene.

foil stamp
A decorating technique that uses dies, heat, pressure and colored foil. The foil image is transferred to the cover creating an upscale graphic effect.

frequency
Rate of change of polarity in alternating current (AC).

G

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gauge
Thickness of plastic in mils or thousandths of an inch.

ground
A conducting body (such as the earth, or an object connected with earth) whose potential is taken as zero and to which an electric circuit can be connected. A stake 4 ' into the earth is a good ground.

H

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hertz (Hz)
Unit of frequency in cycles per second. 60 Hz = ordinary house current. Mega Hertz (MHz) = 1 million cycles per second.

hot stamping
Process in which roll leaf is stamped with heated metal dies onto the plastic.

hub (binders)
The spine or back-bone.

I

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interlock
Safety device used to open circuit and disable machine when doors or covers are open. Make sure that this safety measure is not defeated. Sometimes they are jumped out.

insulator
Non conductive material used to separate or support conductors. i.e. ceramic, mica, bakelite, etc.

J

K

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kilowatt
1000 watts. Machine size / power is given in kilowatts. The amount of kilowatts to seal a given area is figured out 1st by getting the surface area of your die in square inches by multiplying length x width of die or rule. 4 square inches of die = 1 kilowatt of power needed. Sometimes this varies with the thickness and material being sealed. The thinner the material, the more power needed and the more rigid the material, more power is needed.

L

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label holder (binders)
A clear vinyl pocket on the hub into which you can insert a label so as to identify the binder's contents. Some label holders are made of metal.

M

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mechanical
This is final art in which all of the necessary pieces are put in place or position in the exact size and place desired.

mylar (buffer)
Film or tape made of polyester used as buffer. Available in thicknesses from .005" to .015" . It is used for both stationary sealing buffer as well as moving belt buffer for automatic pull-through indexing equipment. Some "tensilized" mylar sheets show significant curling after use, which may be objectionable.

N

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nylon
material used as substrates in supported vinyls.

O

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ohms
Measure of resistance.See Resistance

oscillator circuit
Generates alternating current (AC) power at a frequency determined by the values of certain constants in the capacitors, coil, and tank.

oscillator tube
High power triode tube that produces the r.f. (The workhorse of sealing).

P

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permeability
Diffusion of a vapor or fluid through a porous body without physically affecting it.

plasticizers
Chemical additives used to bond together molecules in plastics to produce desired physical properties.

plate/anode
The electrode on a oscillator tube, to which a principle electron stream flows by means of application of a positive voltage with respect to the cathode (filament). Typical voltages of 8,000 to 12,000 volts.

platen
Upper plate to which a die is usually mounted and is heated to help in sealing and maintain same quality all day long.

PLC
Programmable Logic Controller device used to control machines. Takes the place of relays, timers, clocks, and counters.

pockets (binders)
Any opening built into a binder for storing loose sheets. These can be any size or shape because special dies can create whatever effect you desire.

poly
The short form for polyolefin.

poly binder
A single unit of polyolefin, die cut and scored to form a loose leaf binder. This is often called a flush-cut binder.

polyester
Material used as substrate in supported vinyls.

polymer
Naturally occurring or synthetic substance consisting of giant molecules formed from smaller molecules of the same substance and often having a definite arrangement of the components of giant molecules.

polypropylene
A tough, rigid, light-weight plastic.

poly vinyl chloride (PVC)
A petro-chemical and hydrogen chloride combined. It is widely used in the manufacture of loose leaf binders and other products.

power tube
See oscillator tube

press
Device that uses pneumatics or hydraulics in cylinder(s) to bring down top plate (platen) or seal bar onto the bottom plate with pressure. This is done to assure the bonding of the materials.

PVC
poly vinyl chloride
A petro-chemical and hydrogen chloride combined. It is widely used in the manufacture of loose leaf binders and other products.

Q

R

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radio frequency (R.F.)
Any frequency between normally audible sound waves and the infrared light portion of the spectrum, lying between 10,000 and 1,000,000,000 cycles per second (Hz). R.F. heat sealing machines cycle at around 27 MHz.

r.f. generator
Device that changes line power to a radio frequency.

rectifier
Changes alternating current (AC) to direct current (DC).

relay
Device activated by a variation in conditions in one electrical circuit and controlling a larger current or actuating other devices in the same or other circuit.

resistance
Property of conductors which - depending on their dimensions, material, and temperature - determines the current produced by a given difference of potential; property of a substance which impedes current and results in the dissipation of power in the form of heat. The practical unit of resistance is the ohm.

resistor
A device connected into an electrical circuit to introduce a specified resistance. Some are color coded to show resistance and tolerance.

ring protector (binders)
A "U" shaped piece of fiber or board placed between the rings and the inside cover to keep the rings from punching through the flush-cut cover.

rivets (binders)
Fasteners eyelets used to secure the metal to the binder.

round back (binders)
A concealed rivet binder that has a rounded spine. This is generally a metal component with rivets built into the curve to conceal the rivet head on the binder.

S

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seal & cut - also known as trimbond
A process of sealing and die-cutting simultaneously materials which cannot be tear-sealed with conventional r.f. heat sealing. Hydraulics are added to the machine.

scrim
Open weave cloth used as base for laminated material.

sheet size (binders)
The size of the paper used in the finished product. The "binding edge" size should come first. So, in binder language, you might call for an 11" x 8 1/2" sheet, while printer's language the same sheet would be 8 1/2" x 11".

sheet lifters (binders)
Special hard inserts that fit ring mechanisms to reduce sheet tear-out when opening and closing the covers. These can be made of poly, fiber, or plastic.

shore hardness
Measurement of surface hardness of material.

silicone treated paper (buffer)
Buffer material used in combination with bakelite, fish paper, or mylar. It is placed on top to prevent sticking of PVC material.

silk screen
A direct image stencil used in the color screening process. Early on this was always made of silk. Today that material is rarely used. A different screen is required for each color.

single phase
2 wire AC Circuit

slant D (binders)
Like the D-ring, only slanted.

spine (binders)
Also known as the backbone or hub.

substrate
Cloth that is used as a base for coating or laminating.

supported vinyl
Cloth backed vinyl material that offers strength and heavy wearing qualities.

surface flash
This is sometimes confused with arcing. A flash that occurs on the surface of the material during sealing cycle. This is caused by any combination of these: Press pressure too low or press stop set too high, Power set too high, and the die being too cold. This carbon must be cleaned up good. See Arc

synthetic
Produced by chemical synthesis, rather than of natural origin. Man made such as plastics.

T

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teflon & teflon coated fiberglass (buffer)
A series of specialized buffer materials. Available in thicknesses from .003" to .020". The teflon coated fiberglass may be used as a moving belt buffer material for some applications.

tensile grab
Resistance to delamination from outside force.

tensile strength
Resistance to lengthwise stress, measured (in pounds per square inch) by the greatest load pulling in the direction of length that a given substance can bear without tearing.

tetrahydrofuran
Solvent used for many plastics including vinyl.

thermoplastic
Plastics which can be changed by heat and pressure.

thermoset
plastics which have permanent physical properties not subject to change.

three phase
3 wire AC circuit. Normally 208v to 240v.

thread count
Number of threads per inch in a given direction.

timers
Pre Seal Time delay between press being closed and seal time coming on to ensure proper compression. Usually between 1/2 to 1 sec.

Seal Time that r.f. is on and material is being sealed. Generally you want less time to seal, try more power and less time. It saves wear on the oscillator tube plus you can produce more. Some materials have to be sealed at lower power with more time.

Cool or Dwell Time for material to cool while still under pressure, preventing tearing of hot material. Generally cool time is 1/2 the seal time.

toluene
Used as a solvent for polyurethanes. Very flammable.

top coat
Added to plastic surface, supported or unsupported to give greater weather resistance.

transformer - Abv. XFMR
A device consisting essentially of two or more coils of insulated wire that transfers AC energy by electromagnetic induction from one winding to another at the same frequency but usually with changed voltage and current values. Transformers can step-up or step-down.

triggers (binders)
Also known as boosters on binders.

turned edge (binders)
This is another term for "casebound" , a durable type of construction in which the material is glued to the binders board and the edges of the materials are turned over the board and glued or sealed.

U

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unbalanced material
Coated or laminated material with different thicknesses of plastics on either side.

unsupported vinyl
Simple vinyl without any kind of backing or support material.

UV stabilizer
Chemical added to absorb or diffuse ultra violet. Used in tarps and awnings.

V

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VOM
Volt Ohm Meter used to test resistance and potential.

vinyl
Another term for PVC

voltage
Electromotive force, or difference in electrical potential, expressed in volts.

W

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watt
A measurement of electrical power : Watt = Volt x Amp

X

Y

Z

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